Given the rapid acceptance of packet-based communications, various underlying communication infrastructures are evolving to support packet communications. In particular, cellular networks are evolving to support packet communications over existing wireless access technologies. Regardless of whether additional cellular communications or packet-based communications are supported, a signaling channel and a traffic channel are established between a mobile terminal and a radio access network, which supports communications with the mobile terminal. The signaling channel is a relatively low data rate communications channel that allows the mobile terminal to exchange signaling messages with the radio access network to establish and control communication sessions, which may be traditional cellular communications or packet-based communications. For a communication session, the traffic channel supports the bearer path and may be used to transmit voice information using traditional cellular or packet-based techniques.
For packet-based communications, the mobile terminal generally plays a greater role in call signaling, and in particular, for establishing and controlling packet-based communication sessions involving the mobile terminal. The call signaling messages exchanged with the mobile terminal over the radio access network are relatively longer and more involved than the traditional cellular-based signaling messages. Given the relatively low data rates provided by the radio access network for signaling channels, excessive delays may be incurred during the establishment of a packet-based communication session.
A particularly problematic issue arises when there is an extended delay between the time a caller initiates a call and receives a ringback indicator, which indicates that the called party's terminal is ringing. Currently, the delay between initiating a call and receiving a ringback indicator is much longer than the delay to which callers have grown accustomed. Impatient callers often mistake the extra delay as a malfunction, and prematurely end the call initiation attempt and immediately attempt to reinitiate the call. Such actions result in excessive use of radio access network resources, and the resultant delay frustrates callers.
Accordingly, there is a need for an effective and efficient way to provide a ringback indicator to a caller in response to initiating a packet-based communication session from a mobile terminal.